<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="./jquery.js"></script>
</head>

<body>
    <div class="box">你真是个天才！

    </div>

</body>

</html>
<script>
    var obj = {
        fn: function () {
            $('.box').css('background', 'pink')
            return obj
        },
        fn2: function () {
            $('.box').addClass('add')
            return obj
        },
        fn3: function () {
            $('.box').click(function () {
                alert('总能给点惊喜')
            })
        }
    }
    obj.fn().fn2().fn3()
</script>
<style lang="scss">
    .add {
        width: 300px;
        height: 200px;
        font-size: 40px;
        color: white;
    }
</style>